Long-pulse second-harmonic generation in KTP

Performance and limitations for doubling mode-locked, 1 μm pulse trains in KTP (potassium titanyl phosphate) was experimentally examined. The micropulse length was on the order of 200 ps and the macropulse length was on the order of 100 μs. Conversion efficiencies of 55 percent was achieved with a generated green energy of 190 mJ in 120 μs. An intensity regime for long-term damage-free operation was identified.